Studies on the pathological effects of organisms of the enteritidis paratyphoid B. group on the pancreas,liver and kidneys.

Abstract

During the fall of 1922, in an attempt to produce a streptococcic glomerulo-nephritis it was observed that pathological changes similar in character occurred in both the treated and the control animals. About the same time many of the stock guinea pigs began to die spontaneously and post mortem cultures of their organs and heart's blood yielded Streptococci, Staphylococci and organisms of the Enteritidis-Paratyphoid B. group, but the former were thought to be secondary invaders in a terminal septicæmia. The latter bacilli consisted of two distinct forms namely, B. enteritidis and B. paratyphosus of animal origin, separable by direct agglutination. Microscopic examination of the organs of the animals dying spontaneously showed that characteristic lesions were present in the kidneys, liver and pancreas. On injection of either killed or living bacilli of the Enteritidis-Paratyphoid B. group similar lesions, though more intense and widespread, were likewise obtained.

In the kidneys the most prominent changes occurred in the glomerulus, where considerable intra- and extra-glomerular hemorrhage, thrombosis and varying degrees of necrosis and disintegration were observed. Occasionally hyperplasia of the endothelial lining of the glomerular vessels was present. A marked degree of parenchymatous degeneration occurred primarily in the proximal convoluted tubules and to a less degree in the distal convoluted tubules and the ascending limb of the loop of Henle. In the very acute cases the congestion and hemorrhage had become extreme. Rarely small areas of round celled infiltration occurred.

The liver was characterized by marked congestion, focal necrosis and parenchymatous degeneration. The areas of focal necrosis varied considerably in size, the larger ones having been converted into typical abscesses with thin enveloping walls of fibrous connective tissue. These consisted of varying amounts of necrotic tissue, infiltrated with polymorphonuclear leucocytes mainly, although occasionally endothelial cells were numerous.